Is a jury allowed to find that a two-by-four constitutes a deadly weapon without expert testimony?

Finally, defendant argues that a jury should not be allowed to find that a two-by-four constitutes a deadly weapon without expert testimony. He cites no case actually holding that expert testimony is required. The weight and solidity of a two-by-four, and the amount of strength that can be exerted by a man wielding such a weapon, are matters within common knowledge. The two-by-four itself was in evidence. Thus, expert testimony was not required. (See People v. Madaris (1981) 122 Cal.App.3d 234, 240, disapproved on unrelated grounds in People v. Barrick (1982) 33 Cal.3d 115, 127.)